(Invited) Proton Exchange Membrane Electrolyzers Based on Sub-Micron Thick Membranes

Significant decreases in the price of electricity from solar photovoltaics and wind are enabling concurrent decreases in the cost of clean hydrogen production by water electrolysis. However, to meet the US Department of Energy’s Hydrogen Shot Initiative target for levelized cost of hydrogen production of < $1 per kg of hydrogen by the year 2030,[1] it will also be necessary to drive down the capital costs of water electrolyzers. Reducing capital costs is especially important for scenarios where close to 100% of the electricity is provided by variable renewable energy generators, which greatly limits the capacity factor of the electrolyzer.[2] Towards this end, our team is exploring a proton exchange membrane (PEM) electrolyzer architecture based on ultrathin (< 1 micron) membranes. Modeling is used to show that defect-free membranes possessing appropriate proton and hydrogen transport properties present opportunities to decrease membrane resistances < 80% relative to conventional Nafion membranes, which can subsequently allow for operation at > 4 A cm -2 while maintaining the same efficiencies achieved by today’s commercialized PEM electrolyzers operated at < 2 A cm -2 . Additionally, this talk will describe modeling and experimental efforts that address the viability of using sub-micron thick membranes that can operate with H 2 crossover rates < 1%. References [1] US DOE Hydrogen Shot Initiative: https://www.energy.gov/eere/fuelcells/hydrogen-shot [2] D.V. Esposito, Joule , 1, 1-8, 2017.